1. Field of the Invention
This invention relates to a device, particularly designed to be applied as an accessory to injectors for gas chromatographic columns where the substances to be analysed are introduced by means of an injection syringe, said device being capable of automating at least one of the operations of the injector and/or analytical means downstream the same, due to introduction or drawing back of the syringe.
2. Description of the Prior Art
As it is known, the use of injectors for gas chromatographic columns involves the carrying out, according to the structure and the conditions of injection, of certain operations at the moment of injection and at the end of same. Examples of said operations are opening and closing the injection valve placed inside the channel of some types of injectors; actuating or switching off a secondary cooling device which is used in some types of injectors; opening and closing an exhaust channel, which is open at the end of injection in some types of vaporization injectors; opening or closing an eventual subsidiary injection of carrier gas as performed in correspondence of the valve during injection; and finally switching from feeding conditions at constant pressure to feeding conditions at constant flow of carrier gas. The device can also be coupled with automatic injectors and can even possibly control the flow rate of a sample portion splitting, as well as other functions both of the injector and of analytical means placed downstream the injector itself.
The above mentioned operations are generally performed by the operator who carries out injection of the substance by means of a normal syringe, equipped with a needle which is introduced into the injection channel of injector. However, there is the need to perform these operations with the most possible simultaneousness in relation to the injection syringe introduction or in relation to the drawing back of same. This involves some difficulties for the operator who is already engaged in the delicate operation of sample injection.